pharmacodynamics

potency

at the cellular level, relationship between the concentration of a drug (agonist or antagonist) accessible to cellular receptors and the magnitude of the response of the cell, tissue, or organ to that drug. in vivo: relationship between the dose of a drug and the magnitude of a response. amount of drug required to produce a response of a defined magnitude

Adenylate Cyclase

Affinity

Relationship between the free concentration of a ligand in the vicinity of its receptors and the fraction of the total number of accessible receptors that are bound to the ligand. Both agonists and antagonists have affinity for theirs receptors.

Agonist

Agonist potency

At the cellular level, the relationship between the concentration of an agonist in the vicinity of its receptors and the magnitude of the ensuing response of the cell, tissue, or organ; at the whole-animal or patient level, the relationship between the dose of an agonist drug and the magnitude of the observable response.

Drug

Drug Concentration

Amount of a drug dissolved in blood or other solutions in patients or whole animals, or in perfusing or bathing solutions in isolated cells or organs (expressed in units such as moles per liter [M] or micrograms per deciliter [ug/dL]).

Antagonist

Antagonist potency

At the cellular level, the relationship between the concentration of an antagonist in the vicinity of its receptors and the magnitude of the inhibition of agonist effects on those receptors; at the whole animal or patient level, the relationship between the dose of an antagonist drug and the magnitude of the observable response

receptor down regulation

tachyphylaxis

longer term pharmacodynamic tolerance

super sensitivity/ receptor upregulation

when antagonist causes more receptors to be on the cell surface because agonists cant downregulate/desensitize them so sudden discontinuation will create an influx of agonists to create a heightened response